This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the specification and claims in this application and is not admitted to be prior art by inclusion in this section.
Various abbreviations that appear in the specification and/or in the drawing figures are defined as below:                AP Access Point        AS Access Stratum        ARP Allocation and Retention Priority        BS Base Station        CN Core Network        eNB evolved Node B        E-RAB E-UTRAN Radio Access Bearer        E-UTRAN Evolved Universal Terrestrial Radio Access Network        ECGI E-UTRAN Cell Global Identifier        GPRS General Packet Radio Service        GW Gateway        HLR Home Location Register        HSS Home Subscriber Server        IP Internet Protocol        MME Mobility Management Entity        MSC Mobile Switching Centre        NAS Non Access Stratum        OAM Operations, Administrations and Maintenance        PDU Protocol Data Unit        PLMN Public Land Mobile Network        PCRF Policy and Charging Enforcement Function        QoS Quality of Service        QCI QoS Class Identifier        SCE Small Cell Enhancement        S1AP S1 Application Protocol        TAI Tracking Area Identifier        UE User Equipment        
A UE may connect to an eNB, for example, a macro eNB or a small cell (for example, Femto or Pico cell). The charging for such a connection is done based on UE's subscription information, for example, selected PLMN information associated with relevant QoS guarantee. According to the 3GPP Release 12 SCE, a small cell may be deployed as a separate eNB (known as small eNB) with a non-ideal backhaul connection to the macro eNB. The UE might be able to connect to both macro and small eNBs for dual connectivity operations.